There's a lot of back-and-forth between people who understand immunology (i.e. "not me") about whether the Oxford, Pfizer, or CanSino data released yesterday is the most promising, especially regarding T-Cell count. CanSino (and to a certain extend Moderna, on grounds of the safety profile and T-cell response) are seen as the potential duds currently, but since Phase 3 trials are being run in places where the virus is out of control (Brasil, USA) we probably will know more about this before the summer's over.
By the way, to venture into politics for a second - I belive that Boris Johnson's "back to normal by Christmas" speech late last week would have gone down a lot better if the Oxford vaccine data would have already been available - since the British Press has been speculating a lot about the imminent data release all of last week, he obviously misjudged The Lancet's timing (or The Lancet's editorial board decided not to be part of a political spin).